Weft yarn brake for sulzer loom



Oct. 24, 1967 G. J. BRooKsHlRE 3,348,582

` WEFT YARN BRAKE FOR SULZER LOOM l Filed sept. 27, 1965 INV ENTOR.-

ATTORNEYS United States Patent Office 3,348,582 Patented Oct. 24, 1967 3,348,582 WEFT YARN BRAKE FOR SULZER LOOM Grover J. Brookshire, Blue Ridge Road, Black Mountain, N.C. 28711 Filed Sept. 27, 1965, Ser. No. 490,432 1 Claim. (Cl. 139-194) ABSTRACT F THE DISCLOSURE A weft yarn braking device for clampingly engaging the weft yarn in a Sulzer loom and wherein the yarn engaging elements have wear resistant surfaces each being carried by resilient pads with one pad being of more resiliency than the other to compensate for any misalignment of the elements while providing a gradual braking pressure to the yarn for positively stopping the yarn.

This invention relates to an improved weft or filling yarn braking device for Sulzer looms. Y The conventional weft yarn braking device of a Sulzer loom is shown in the U.S. Patent to Pfarrwaller No. 2,749,946, issued lune 12, 1956. This conventional brake includes a flexible brake band over which the weft yarn is guided as it is withdrawn from the supply spool and carried across the loom, and a movable brake shoe which moves down to clamp the weft yarn against the flexible brake band upon completion lof the insertion of the weft yarn by the gripper shuttle passing through the open shed. Repeated contact of the brake shoe with the brake band causes the brake band to wear out in a relatively short time so that it must be frequently replaced. While other types of weft yarn braking devices have been utilized, they have not met with any substantial degree of commercial success because they do not provide the required positive grip on the yarn 'or they do not provide the desired degree of gradual braking pressure on the yarn as the shuttle moves into the shuttle receiving unit housing on the opposite side of the loom.

With the foregoing in mind, it is a main object of the present invention to provide an improved weft yarn braking device which is not subject to the wearing problems of conventional braking devices and which provides the desired type of braking action to be applied to the weft yarn.

It is a more specific object of the present invention to provide an improved braking device-of the type described which includes a pair of brake elements positioned on opposite sides of the weft yarn as it is withdrawn from the supply spool and carried across the loom and means for moving the brake elements together to move into clamping engagement with the weft yarn iny timed relationship with the periodic withdrawal and insertion of the weft yarn, and wherein each of the barke elements includes a wear-resistant brake pad that is resiliently suported.

Some of the objects of the invention having been stated, other objects will appear as the description proceeds, when taken in connection with the accompanying drawings, in which:

FIGURE 1 is a somewhat schematic perspective view of a fragmentary portion of one end of a Sulzer loom illustrating the manner in which lthe weft yarns are withdrawn from the respective supply spools and pass through the braking devices as they are carried across the loom;

FIGURE 3 is an enlarged isometric View of one of the braking devices shown in FIGURE 1 and with the movable brake element in a raised position out of gripping engagement with the other brake element; and

FIGURE 3 is a vertical sectional view through the braking device taken substantialy along the line 3-3, but illustrating the upper movable brake element in a lowered position and gripping the weft yarn against the rixed brake element.

Only those portions of the Sulzer loom are illustrated in FIGURE 1 that are necessary to an understanding of the present improved braking device. The weft yarns, indicated at W, W are selectively carried across the loom by a gripper type shuttle, not shown, in a well-known manner and the weft yarns are withdrawn from respective supply spools 10 and 10. The weft yarns W, W', are drawn through respective braking devices, broadly indicated at 15, 15' which are identical and operated in timed relationship to the periodic withdrawal yof the respective weft yarns. Y

The braking devices 15, 15' are each operated by identical control means and only the control means associated with braking device 15 will be described in detail While corresponding reference numerals with the prime notation added will be applied to like parts of the control means for the brake 15. A release and braking lever 16 is pivotally supported adjacent one end on the loom frame as at 17 and the other end supports one of the brake elements, to be presently described. The lever 16 is connected to the outer end of a control link 18, the inner end of which is provided with an operating roller 19 that rides on the peripheral surface of a cam wheel 21. The cam wheel 21 is xed on a control shaft 22 which is rotated in timed relationship to insertion of the weft yarn in the loom shed.

The roller 19 is resiliently urged into engagement with the surface fof the cam wheel 21 by means of a lever 24, the -upper end of which is suitably connected to the connecting link 18 and the lower end of which is pivotally supporte-d on the frame 25 of the loom. A tension spring 26 is connected between a medial portion of the lever 24 and the frame 25 to thereby maintain the roller 19 in resilient engagement with the outer surface of the cam wheel 21.

As best shown in FIGURES 2 and 3, the braking device 15 includes rst and second brake elements supported adjacent the path of travel of the weft yarn W as it is withdrawn from the supply spool 10 and inserted in the shed of the loom. These brake elements operate to clamp and release the weft yarn W in timed relationship to the periodic withdrawal of the weft yarn and the operation of the other loom elements. The first brake element is preferably supported in a xed position on the frame of the loom and includes a horizontally disposed support bracket 30 which has the upper end of a vertically disposed support arm 31 suitably secured to one end thereof. The lower portion of the support arm 31 is provided with slotted holes 31a that are adapted to receive mounting screws so that the first brake element may be adjustably supported on a fixed portion of the lo-om, not shown.

Spaced apart upstanding plates 32, 33 and 34 are suitably supported at their lower ends on the bracket 30 and are provided with respective yarn guide eyes 35,36 and 37. The yarn W is guided through the eyes 35-37 so that it passes above a first brake shloe element which includes a rm rubber pad 40 having its lower surface fixed to the bracket 30, a steel plate 41 having its lower surface lixed on the upper surface of the rubber pad 40, and a ceramic or porcelain brake pad 42 having its lower surface fixed on the upper surface of the plate 41 (FIG- URE 3).

The second or movable brake element includes an angle bracket 44 which has a Vertical leg that is suitably secured to the inner end of the release and braking lever 16. The horizontal leg of the bracket 44 supports a second brake shoe element that is positioned above the first brake shoe element and is raised to the posi- 3 tion shown in FIGURE 2 when the yarn W is being withdrawn from the supply spool 10.

The second brake shoe element includes a resilient sponge rubber pad 4S which is preferably softer and more yieldable than the resilient firm rubber :pad 40 of the first brake shoe element and the upper surface of the resilient pad 45 is fixed to the bracket 44. A steel plate 46 is secured to the lower surface of the resilient pad 45 and a ceramic or porcelain brake pad 47 is secured to the lower surface of the plate 46. As the upper brake pad 47 moves downwardly toward the lower brake pad 42, it initially applies a gradual braking action to the yarn and then rmly clamps the yarn as the sponge rubber pad 45 is compressed, as shown in FIGURE 3.

During normal operation of the loom, the inner free end of the release and braking lever 16 is raised and lowered in timed relationship to withdrawal of the weft yarn W from the supply spool and the passage of the weft yarn W lacross the loom. As the roller 19 moves into and then out of the lower portion of the cam wheel 21 (FIGURE l), the free end of the lever 16 is raised and then lowered. As the shuttle, not shown, approaches the shuttle receiving unit housing at the opposite end of the loom, the release `and braking arm 16 moves downwardly so that the upper braking pad 47 first engages and moves the yarn W down against the lower braking pad 42. Then, with further downward movement of the release and braking lever 16, the more yieldable, resilient pad 45 is compressed to finally clamp and completely stop the yarn W. The resilient pads 40, 45 also permit the brake shoe pads 42, 47 to properly seat themselves, regardless `of any slight error in the mounting of the brackets 30, 44 or any misalignment of the parts.

The parts of each of the brake shoe elements are preferably secured together by a suitable type of glue and they are preferably rectangular in shape, however, they may be secured together by other suitable means and they may be oval, round or any other 4desired shape. Although the pads 40, 45 have been described as being rubber, it is to be understood that they may be formed of other non-metallic resilient material, such as synthetic rubber, soft plastics, and the like. Also, the brake pads 42, 47 may be omitted if a suitable wear-resistant surface is provided on the yarn engaging surfaces of the resilient pads 40, 45.

Since the guide eyes 36, 37 are positioned `closely adjacent opposite sides of the lower brake pad 42, the weft yarn W is maintained in position above the same so that it will be engaged by the upper brake pad 47. It is particularly important that the guide eyes 36, 37 be positioned closely adjacent the brake pads when blower type overhead cleaners are used. Otherwise, the blast of 4 air from the cleaner will blow the weft yarn W out of alignment with the brake elements to render the same ineffective.

In the drawings and specification there has been set forth a preferred embodiment of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for Ipurposes of limitation, the scope of the invention being defined in the claim.

I claim:

In a Sulzer loom having means for periodically withdrawing weft yarn from a supply spool and carrying the weft yarn across the loom, a brake operating level, and cam rcontrolled means for reciprocating one end of said operating lever in timed relationship to the periodic withdrawal of the weft yarn, the combination therewith of an improved weft brake comprising:

(a) a iirst brake element supported adjacent the path of travel of the weft yarn as it is withdrawn from the supply spool, said first brake element including (1) a support bracket,

(2) a resilient pad fixed on `said support bracket,

(3) a wear-resistant brake pad fixed on said resilient pad, and

(4) yarn guide means positioned closely adjacent opposite sides of said brake pad for guiding the weft yarn across said brake pad, and (b) a second brake element including:

(1) a support bracket carried by said one end of the said reciprocating brake operating lever, (2) a resilient pad xed on said support bracket,

and

(3) a wear-resistant brake pad Xed on said resilient pad and aligned with the brake paid of said first brake element to lmove into and out of engagement therewith in timed relationship to withdrawal of the weft yarn to thereby clamp and release the weft yarn, and

(c) the resilient pad lof one of said brake elements being formed of a much more yieldably material than the resilient pad of the other brake ele-ment,

References Cited UNITED STATES PATENTS 2,276,408 3/ 1942 Marcora 242-l49 X 2,537,476 1/1951 Moessinger 242-149 2,749,946 6/ 1956 Pfarrwaller 139-126 2,819,736 1/ 1958 Pfarrwaller 139-l94 3,181,569 5/1965 Carroll 139l22 MARVIN STEIN, Primary Examiner.

I. KEE CHI, Asstcmt Examiner. 

